OP I'm glad you have a plan but I think you need to be really careful. This kind of thing shows he's manipulative and being very cunning about keeping you in your place (which is dependant on him with little life of your own):
Yes I have. He takes offense every time, says he pays all the bills, gives me his money when I need to go grocery shopping, says I'm making him look like the bad guy when he's fully providing for me.
It was only earlier this year that I started mentioning that now all 3 were primary aged and not so dependant, that I might look into part time study or work that he came around to the idea of another. Although now, its pretty obvious why he changed his mind.
Looking back Im seeing a pattern of keeping me dangling - no point joining clubs or making friends, we'll be moving again soon.
He doesn't "fully provide for you". He gives you the minimum amount of money so that you and HIS children can eat. He's set up your lives to ensure that you can't work (and have put all your time and energy into looking after the children and running the household) but he begrudges you the cost of small things like a haircut.
I think its great that you're making plans that will help you gain financial independence but be prepared for him to push back against those plans. He has his life and you right where he wants it now, he's clearly not stupid and he clearly doesn't care very much about what you want or your feelings.
He WILL try to block any moves you make that don't suit him, like you spending time studying or doing paid work. If settling down somewhere when the kids are older gives you opportunities to be more independent he WILL block it - suddenly it will be a bad time in his career to settle and you'll need to keep moving or some other BS.